I can understand why you feel Washington is a place of “petty nonsense,” as you said last week when you called a news conference to rebut charges that you called Donald Trump a moron last summer at a meeting of national security officials at the Pentagon.

I’m also reasonably sure you called him a moron, which doesn’t make Washington any less petty. You probably called him a moron because almost all of us out here in the rest of America routinely call him that.

But you’re right: There are far more important issues than the epithet you likely used to describe your boss.

On the other hand, your calling him a moron wouldn’t itself have mushroomed into a headline issue if there weren’t deep concerns about the president’s state of mind to begin with.

The reason your moronic comment about Trump made the headlines is that Trump really is a moron, at least in the sense in which you probably meant it: He’s impulsive, mercurial, often cruel and pathologically narcissistic. Some psychologists who have studied his behavior have concluded he’s a sociopath.

Washington is petty, but it’s not nonsensical. It latches on to gaffes only when they reveal something important. As journalist Michael Kinsley once said, “A gaffe is when a politician tells some obvious truth he isn’t supposed to say.”

Face it: You are Secretary of State under a president who’s dangerously nuts.

Earlier this month, for example, Trump publicly said you were wasting your time trying to open talks with North Korea. Does he have a better idea? Any halfway rational president would ask his secretary of state to try to talk with Kim Jong Un.

And there’s Iran. You and Defense Secretary James Mattis have both stated that the nuclear agreement should be retained. That, too, is only rational. The International Atomic Energy Agency says Iran has been honoring the agreement. Without it, Iran would restart its nuclear program.

But Trump is on the verge of decertifying the agreement in order to save face (in the 2016 campaign he called it an “embarrassment to America”) and further puncture Barack Obama’s legacy. Trump’s narcissism is endangering the world.

You tried to mediate the dispute between Qatar and its Arab neighbors. That, too, was the reasonable thing to do. But then Trump and his son-in-law, Jared Kushner, sided with the United Arab Emirates, where they have business interests. Only about an hour after you called for a “calm and thoughtful dialogue” between Qatar and its neighbors, Trump blasted Qatar for financing terrorism. That was also nuts.

Robert Reich(Photo: Special to the Register)

Given all this, I’m not surprised to hear that you’ve talked about resigning, but that Mattis and John Kelly, the White House chief of staff, have talked you out of it.

I urge you not to resign. America and the world need sane voices speaking into the ear of our narcissist-in-chief.

As Sen. Bob Corker, the Tennessee Republican who chairs the Senate Foreign Relations Committee said recently, it’s you, Mattis and Kelly who “help separate our country from chaos.”

In a recent interview with the New York Times, Corker said Trump was treating his office like “a reality show,” and his reckless threats toward other countries could set the nation “on the path to World War III.”

“He concerns me,” Corker said. “He would have to concern anyone who cares about our nation.”

Let Trump fire you if he wants to. That would further reveal what a moron he is.

If you really did want to serve the best interests of this nation, there’s another option you might want to consider.

Quietly meet with Mattis, Kelly and Vice President Mike Pence. Come up with a plan for getting most of the Cabinet to join in a letter to Congress saying that Trump is unable to discharge the duties of his office.

Under the 25th Amendment, that would mean Trump is fired.

Robert Reich, a former U.S. Secretary of Labor, is professor of public policy at the University of California at Berkeley.